摘要
用普通小麦“中国春”双端二体系列(double ditelosomics)作母本分别与西藏小麦杂交,对全套21个F_1的PMC在MI进行端体配对分析。在(“中国春”双端二体7B×西藏小麦)F_1中,含有(t′,t1″)构型的PMC占观察总数的87.3％,7BS常不参与配对,显示出有较大差异。“中国春”3A、7A、2D—7D等8条染色体的两臂可以分别同时与西藏小麦对应染色体配成异型三价体(tt1′′′)的PMC频率达80.0—95.5％,表明西藏小麦与“中国春”之间这8条染色体差异很小。在涉及其余12条染色体的组合中,出现(tt1′′′)、(t′t1″)和(t′,t′)构型的PMC分别占观察细胞总数的42.3—77.6％、21.9—55.5％和0—8.0％,表明它们之间仅某个染色体臂间有轻度变异或分化。从总体来看,西藏小麦与“中国春”之间除7BS有较大差异外在染色体构成上基本相似。
Meiotic analysis of PMCs at Ml was conducted on the whole set of twenty-one hybrids of Xizang wheat (Triticum aestivum ssp. tibetanum Shao) with double ditelosomics of Chinese Spring (CS ddt). In the hybrid of CS ddt 7B with Xizang wheat, the PMCs with (t', tl') amounted to 87.3% and it was found that 7BS of CS always failed to pair with its counterpart in Xizang wheat. It is consequently suggested that substantial differentiation might have oc-cured on this arm. Both arms of eight chromosomes (3A, 7A, 2D-7D) of CS could pair readily with their corresponding ones in Xizang wheat, forming heteromorphic trivalents (ttl'''), which explains that differentiation has rarely occured between these eight chromosomes of Xizang wheat and Chinese Spring. In the hybrids involving the remaining 12 chromosomes, the frequencies of PMCs with (ttl'''), (t', tl') and (t', t') were 42-3-72.6%, 21.9-55.5% and 0-8% respectively, showing that only slight differentiation or changes have happened with some chromosome arms of Xizang wheat. In general, Xizang wheat showes a basically similar chromosome constitution with Chinese Spring.
基金
中国科学院科学基金
关键词
西藏小麦
染色体构成
非整倍体分析
Xizang Wheat (Triticum aestivum spp. tibetanum Shao), Chromosome constitution, Aneuploid analysis
